Efficient Catalytic Conversion of Dinitrogen to N(SiMe3)3 Using a Homogeneous Mononuclear Cobalt Complex

Incorporation of the tridentate phosphine-enamidoiminophosphorane onto cobalt­(II) produces tetrahedral Co­(NpNPiPr)­Cl, 1, which upon reduction under dinitrogen generates the T-shaped, paramagnetic Co­(I) complex Co­(NpNPiPr), 2. This paramagnetic T-shaped derivative is in equilibrium with the paramagnetic dinitrogen derivative Co­(NpNPiPr)­(N2), 3, which can be detected by IR and low-temperature UV–vis spectroscopy. Both 1 and 2 act as homogeneous catalysts for the conversion of molecular nitrogen into tris­(trimethylsilyl)­amine (N­(SiMe3)3) (∼200 equiv, quantified as NH4Cl after hydrolysis) in the presence of excess KC8 and Me3SiCl at low temperatures.